Described herein is a method for depositing a stoichiometric or non-stoichiometric metal or a metalloid nitride film of a metal from Group 13 of the Periodic Table using one or more Group 13 metal or metalloid precursors. More specifically, described herein are plasma-based methods for depositing films including, but not limited to, plasma enhanced atomic layer deposition (“PEALD”), and PEALD-like plasma enhanced cyclic chemical vapor deposition (“PECCVD”) methods that are typically used for depositing Group 13 metal or metalloid films such as aluminum, gallium, indium, thallium, boron, or combinations thereof that can be used, for example, in the fabrication of integrated circuit devices. Because of its combination of unique properties, Group 13 containing metals of metalloid films such as, without limitation, aluminum nitride (AlN) or boron nitride (BN) films can be used for a variety of electronic applications.
The prior art provides different methods for preparing and using Group 13 metal or metalloid films such as AlN films. For example, the reference “The influence of N2/H2 and ammonia N source materials on optical and structural properties of AlN films grown by plasma enhanced atomic layer deposition,” Alevli, M., et al., J. Cryst. Growth, Vol. 335(1): 51-57 (2011), discloses the influence of N2/H2 and ammonia as N source materials on the properties of AlN films grown by plasma enhanced at. layer deposition using trimethylaluminum as the metal. The AlN growth rate per cycle was decreased from 0.84 to 0.54 Å/cycle when the N source was changed from NH3 to N2/H2. Growth rate of AlN remained constant within 100-200° C. for both N precursors, confirming the self-limiting growth mode in the ALD window.
The reference “Optical properties of AlN thin films grown by plasma enhanced atomic layer deposition,” Alevli, M., et al., J. Vac. Sci. Technol., A, Vol 30(2): 021506/021501-021506/021506 discloses crystalline aluminum nitride (AlN) films that were prepared by plasma enhanced atomic layer deposition within the temperature range of 100 and 500° C. The reference shows a relationship between growth temperature and optical properties and the refractive indexes of the AlN films were larger than 1.9 within the 300-1000 nm wavelength range.
The reference, “PEALD AlN: Controlling growth and film crystallinity,” Banerjee, S. et al., Physica Status Solidi (C) Current Topics in Solid State Physics, discloses the growth kinetics and material properties of aluminium nitride (AlN) films deposited on Si(111), with plasma enhanced atomic layer deposition (PEALD). Tri-methyl aluminum (TMA) and NH3-plasma were used as the precursors.
The reference, “Atomic layer deposition of AlN for thin membranes using trimethylaluminum and H2/N2 plasma,” Goerke, S., et al., Applied Surface Science Vol. 338(0): 35-41 (2015), describes a method for depositing aluminum nitride (AlN) thin films with thicknesses from 20 to 100 nm were deposited on silicon, amorphous silica, silicon nitride, and vitreous carbon by plasma enhanced atomic layer deposition (PE-ALD) using trimethylaluminum (TMA) and a H2/N2 plasma mixture.
The reference, “Atomic Layer Deposition of AlN with Tris(Dimethylamido)aluminum and NH3,” Liu, G., et al., ECS Transactions 41(2): 219-225 (2011) discloses atomic layer deposition of aluminum nitride on Si wafers using tris(dimethylamido)aluminum and ammonia has been investigated in the temperature range from 180 to 400° C.
The reference, “Structural and optical characterization of low-temperature ALD crystalline AlN,” Motamedi, P. et al., J. Cryst. Growth 421: 45-52 (2015) describes a plasma enhanced atomic layer deposition (PEALD) process has been used to deposit crystalline AlN thin films at 250° C. using nitrogen 5% hydrogen plasma and trimethylaluminum precursors. Films grown on single crystal silicon and sapphire substrates are crystalline with strong (100) preferred orientation.
The reference, “Self-limiting low-temperature growth of crystalline AlN thin films by plasma-enhanced atomic layer deposition,” Ozgit, C., et al., Thin Solid Films 520(7): 2750-2755 (2012) described PEALD depositions of aluminum-containing films on various substrates using AlMe3 and NH3.
The reference, “Influence of plasma chemistry on impurity incorporation in AlN prepared by plasma enhanced atomic layer deposition,” Perros, A. P., et al., Journal of Physics D: Applied Physics 46(50): 505502 described PEALD depositions of AlN films using NH3, N2/H2, and N2 plasmas and TMA as the precursor. Different atomistic growth mechanisms are found to exist between the plasma chemistries. The N2 plasma is shown as not suitable for the low-temperature deposition of AlN. Films deposited by NH3- and N2/H2-based processes are nitrogen rich and heavily hydrogenated. Carbon impurities exist at higher concentrations for the N2/H2-processes. The discovery of nitrile groups in the films indicates that carbon impurities can be partially attributed to an undesirable reaction occurring during the plasma step between nitrogen species and CH groups.
The reference, “Structural properties of AlN films deposited by plasma-enhanced atomic layer deposition at different growth temperatures,” Alevli, M., et al., Phys. Status Solidi A 209(2): 266-271 (2012) describes the preparation of crystalline aluminum nitride (AlN) films by PEALD within the temp. range from 100° to 500° C.
The reference, “Deposition and characterization of BN/Si(001) using tris(dimethylamino)borane,” Dumont, H. et al., Mater. Res. Bull. Vol. 37(9), pp. 1565-1572 (2002), describes using a chemical vapor deposition process to deposit BN thins films on Si(001) at temperatures ranging from 750° C. and 1000° C. using (tris(dimethylamino)borane as the precursor.
U.S. Pat. No. 7,141,500 discloses a method of forming an aluminum containing film such as aluminum oxide, aluminum nitride, or aluminum oxynitride on a substrate comprising: providing a precursor having the structure Al(NR1R2)(NR3R4)(NR5R6) where each of R1, R2, R3, R4, R5, and R6 is independently selected from the group consisting of hydrogen and an alkyl group including at least 2 carbon atoms. Each of the R1-R6 groups can be the same or different and can by straight or branched chain alkyls. An exemplary precursor that is useful in forming Al containing films is trisdiethylamino aluminum.
US Pub. No. 2005/0208718 discloses a method for forming a capacitor using an atomic layer deposition (ALD) process include providing a reactant including an Al precursor onto a substrate to chemisorb a portion of the reactant to a surface of the substrate. An NH3 plasma is provided onto the substrate to form a dielectric layer including Al nitride on the substrate including the lower electrode.
Accordingly, there is a need in the art to provide a low temperature (e.g., processing temperature of 400° C. or below) method for depositing a conformal, high quality, aluminum nitride film wherein the film has one or more of the following characteristics: a density of 2.4 grams per cubic centimeter (g/cc) or greater, a low wet etch rate (as measured in dilute hydrofluoric acid (HF)), hydrogen content less than 20 at. %, reflective index greater than 2.00 and combinations thereof compared to other aluminum nitride films using other deposition methods.